1. Field of the Invention
When desiring to initiate intravenous therapy, a person rendering the therapy must find a vein on a patient into which a needle may be introduced for use in carrying out the desired intravenous therapy.
It is now common practice to use a rubber tourniquet applied about an upper portion of a body limb for the purpose of restricting venous return of blood from that limb to the torso. When cardiac output is sufficient, the veins distal to the tourniquet become hyperextended as they fill with blood that is being pumped to their connecting arteries of the veins. The hyperstatic pressure created by the heart forces the blood through the arteries that lie underneath the tourniquet. Blood continues through the arterioles, capillaries, venules, and then the veins distal to the tourniquet. The constricting band action of the tourniquet limits or prevents the return of that blood to the heart. Then a hypertensive action becomes apparent as the veins distal to the tourniquet become engorged with blood and hyperextended. It is at this time that a needle may be introduced into a hyperextended vein for the purpose of intravenous therapy.
However, when a patient has substantially no cardiac output, a tourniquet is not operative to cause a vein to be hyperextended in order to facilitate the starting of intravenous therapy. When substantially no cardiac output is present the veins are substantially collapsed and only the arteries of a body limb disposed considerably below skin surface have any appreciable amount of blood therein. Accordingly, in many instances, paramedics, nurses and doctors attempting to introduce a needle into a vein are unable to find such a vein. Of course, time lost in starting intravenous therapy under these conditions often is a matter of life or death. A doctor may try several minutes in a critical situation and then, as a last resort, attempt to introduce the needle into a femoral artery or perform a "cut down" (minor surgical procedure) or may do a subclavian. All of these procedures are time consuming and the accumulative loss in time may be critical.
Accordingly, a need exists for a means by which a suitable vein may be engorged with blood and thus hyperextended, even when the patient has little or no cardiac output.
2. Description of the Related Art
While there have been many different forms of tourniquets heretofore utilized, none of the previously used forms of tourniquets are operative, on a patient with substantially no cardiac output, to engorge a vein with blood so as to present a hyperextended vein into which a needle may be readily introduced for intravenous therapy. Examples of previously known forms of tourniquets and similar structures are disclosed in U.S. Pat. Nos. 1,757,060, 2,091,131, 2,511,269, 3,467,077, 3,570,495, 3,586,001, 3,587,584, 3,654,931 and 4,066,084.
The massaging apparatus disclosed in U.S. Pat. No. 2,091,131 comprises a roller assembly adapted to be encircled about a body limb such as an arm and to be rolled up and down the arm as a massaging device, the massaging device incorporating relative soft and porous rollers so as to massage and knead the body of the patient in a gentle manner, which massaging action is not effective to carry out the objects of the instant invention and which gentle manner is likewise ineffective to carry the objects of the instant invention.
Still further, U.S. Pat. No. 4,066,084 to Tillander is designed specifically to gradually upwardly compress circumferential zones of a body limb in order to empty blood from the limb extremity toward the heart of a patient prior to surgical incision. Inasmuch as this apparatus is designed to empty the blood from a limb extremity toward the heart of a patient it accomplishes the exact opposite of the instant invention which is designed to engorge a vein toward the extremity of a limb by milking not only any small amount of venous blood toward the limb extremity but also milking deeper level arterial blood toward the extremity. Further, the Tillander apparatus substantially totally encloses the portion of the limb to which it is applied, thereby preventing any access to an underlying vein. Further, because of the shape of the Tillander apparatus it is not reversible on the extremity for operation in emptying blood from a limb toward the extremity thereof.